Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to figure out when it's the best time to plant yarrow by referring to the USDA zone info for South San Francisco.

Planting Calendar for Yarrow

Frost tolerance for yarrow:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Yarrow are very cold tolerant which tells us that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant yarrow in South San Francisco is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant yarrow and expect a good harvest is probably October. You probably don't want to wait any later than that or else your yarrow may not have a chance to grow to maturity. Starting your yarrow indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In South San Francisco the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Keep in mind that USDA zone info for South San Francisco is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in South San Francisco there is a last frost after January 31 so make sure that you are ready to protect your yarrow in the event of one of those late frosts.

USDA Zone Info for South San Francisco

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in South San Francisco

You may be interested in your other planting guides for South San Francisco.